他的论点纯属理论，缺乏任何实证依据。

His argument is purely ___theoretical and lacks any empirical evidence.

这门课程侧重于量子力学的理论基础。

The course focused on the ___theoretical foundations of quantum mechanics.

在实施该政策之前，我们必须超越理论讨论，考虑实际限制。

Before implementing the policy, we must move beyond ___theoretical discussions and consider practical constraints.